Correlation of wrist ligamentotaxis with carpal distraction: implications for external fixation.
Cadaver forearms were tested to measure carpal bone separation and wrist ligament tension in response to MTS-based incremental wrist distraction. Distraction of 2 mm separated the proximal carpal row from the radius and transmitted an average tension of 8 N. The mid-carpal joint also began to widen at this level of distraction. Distraction of 4 mm resulted in an average tension of 20 N. At this level of distraction, radioscaphoid separation started to exceed radiolunate separation. A transition from low- to high-stiffness response was observed over a range of 4-8 mm distraction for the 12 specimens tested, with an average tension of 80 N associated with 8 mm distraction. Average values of carpal height ratio, revised carpal height ratio, and carpal height index were found to be poor indicators of distraction, owing to their high variability between specimens.
Loebig
T G
TG
Biomechanics Research Laboratory, Allegheny-Singer Research Institute, Pittsburgh, PA, USA.
Badia
A
A
Anderson
D D
DD
Baratz
M E
ME
D002102:Cadaver; D002348:Carpal Bones / Q000293:injuries; D005592:Fracture Fixation; D006801:Humans; D008023:Ligaments, Articular; D014955:Wrist Joint